We report on the results of testing a hybrid subnanosecond modulator with an input resistance of 50 Ω based on an all-solid-state high-voltage nanosecond-pulse charging source with an inductive energy accumulator, a semiconductor current switch, and a pulse shaper with gas-discharge gaps. Use of the sharpening and cutting discharge gaps filled with hydrogen at a pressure of 100 atm ensured the stable formation of pulses with a peak amplitude of up to 140 kV and a pulse width of ∼500 ps at a repetition rate of up to 2 kHz.